Aggression in the home, but not outside.

I adopted a 1 y/o male Great Dane/Lab mix 4 months ago. He came from an abusive situation and was in foster with a great rescue. The foster only had him for 2 weeks before we adopted him. Jet is a wonderful and loving dog and listens very well. He also takes correction very well. In the last month though, he has become very protective inside the home when people come over. He will growl, lunge, and attempt to bite. He has done this even with people he knows. I have to put him in the bedroom when I have company. Anywhere outside the home, including the yard, pet store, play dates, etc.. Jet is his normal happy go lucky self with everyone. Even the same people he has issue with inside.I am stumped as to the change in his behavior. The only thing different is that there is a work crew fixing a small bridge at the end of my long driveway. He appears to be afraid of the heavy equipment. This all started about the same time the work crew showed up. My friend and I did a test today with Jet. She came in and he was very aggressive towards her with his hair standing straight up and trying to lunge. Jet knows her and has been around her many times. My friend went outside and then I bought Jet outside on the leash and he was thrilled to see her. Butt wags and puppy kisses. My friend took the leash and walked around with him. Offered up cheddar cheese for a paw and a sit. then she took him into the house after I went in. She made him do a couple more sits for cheese and let him off the leash and went and sat down. He was completely fine and was his happy self. I don't understand what could have caused this change. Any more suggestions and insight you could offer would be greatly appreciated. Thank you.

I have the EXACT situation with a 6 year old boxer i resuced. It's like they have to completely different personalities when they're in the home or out in public, right? What I've been told by various trainers is my dog has territorial aggression with also fear aggression. Basically they don't trust people because of the abusive situations they've been in. I find it eaiser to have him on a leash out in the driveway when visitors arrive. I let him stand outside with them a little while and when he calms down we move inside. I still keep him on a leash at his point. I have the visitor give him a treat, and once I'm sure he's not going to get aggressive I let him off the leash. If he is still acting aggressive I put him in a "time out" in another room for 15 min. or so and then try again. I'm still working with my dog on these issues but unfortunately he's been in a bad situation for 6 years so I've been told by my trainer somethings we won't be able to reverse. I'm glad you were able to adopt you're dog sooner . best of luck!

So happy to hear that your dogs are adopted ones We need more people like you both.

Yes, like Hailey said some dogs with bad histories are a bit too broken to be fixed completely. But you know what? Time and love are great healers and so with a little understanding and patience, most behaviours can be dramatically altered.

I have to admit that fear-based aggression is the most dangerous kind so please be alert and aware at all times. Safety always comes first. Leashes are handy things to have on these dogs so that they can be easily controlled if things go wrong. Muzzles/head collars are useful too.

Deborah, what you're getting your friend to do is very good and you may want to ask her to do so more frequently. Once he is okay with her, get another animal-enthusiast friend to come around and do the same. Time outs are great to help them calm down and praise and treats are great for encouragement.

Remember, puppy-steps. Keep the sessions short. Be the alpha-dog and don't ever forget that these dogs have had hard pasts. It isn't their fault that there are fearful